I recently started studying with a great "old school" Simandl teacher. He keeps yelling at me to use my 3rd finger "as a unit" with my 4th, and I find that very awkward, but it may be just because it is new to me. Usually my 3rd finger just hangs out over the strings until I get to the 4th position where I start using a four finger method. I just don't see the logic in using 2 fingers at a time when my 4th finger does the job fine by itself, plus when the 4th is used, the 1 and 2 are usually already pressing the strings. What do you people think about the "3rd and 4th as a unit" in particular? I could understand that it was used back in the day when action was way higher........